X3T9.2/89-023 January 14, 1989 Mr. John Lohmeyer Chairman X3T9.2 NCR MS21 3718 N. Rock Road Wichita KS 67226 Dear John, Following is the text of the changes to ESDI to incorporate the proposal by Hitachi America to offset sector location with synchronized spindles. | 7.18.3 Synchronized Sector Offset | | When set to a value other than zero, the slave drive shall offset its | synchronized position by the number specified e.g. if set to 64, the | slave drive shall offset its position by one quarter rotation beyond that | of the master. TABLE 30: SET CONFIGURATION SOFT SWITCH PARAMETER BITS ======================================================================= +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ |15 |14 |13 |12 |11 |10 | 9 | 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 | P | +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ | CMD Function | Switch No | Switch Parameter | +---------------+---------------+-----------------------------------+ | 1 1 1 0 | / / / / / / / / | | 1 1 0 0 | Set Synchronized Drive | | | | x'00' = Slave | | | | x'01' = Master | | | 1 1 0 1 | Notched Drive Zone Number | | | | 1 1 1 0 | Synchronized Sector Offset | | | 1 1 1 1 | Reserved = 0 | +---------------+ / / / / / / / / ========================================================================== Yours sincerely, I. Dal Allan